Response of greenhouse gas emissions and microbial community dynamics to temperature variation during partial nitrification.

This study investigated the greenhouse gas emission characteristics and microbial community dynamics with the variation of temperature during partial nitrification. Low temperature weakened nitrite accumulation, and partial nitrification would shift to complete nitrification easily at 15 °C. Based on CO equivalents (CO-eq), partial nitrification process released 2.7 g of greenhouse gases per gMLSS per cycle, and NO accounted for more than 98% of the total CO-eq emission. The total CO-eq emission amount at 35 °C was 45.6% and 153.4% higher than that at 25 °C and 15 °C, respectively. During partial nitrification, the microbial community diversity greatly declined compared with seed sludge. However, the diversity was enhanced at low temperature. The abundance of Betaproteobacteria at class level increased greatly during partial nitrification. Proteobacteria abundance declined while Nitrospira raised at low temperature. The nosZ community abundance was not affected by temperature, although NO emission was varied with the operating temperature.